I just got back from a long break from this game . What Skills should i invest in a Blizzard MF Sorc other than blizzard and its synergies?

Should I try to attain 105 FCR break-point or keep at 63?

Also - Which A2 Merc Aura should i roll with? Thanks.

Stick to basic setup toward lvl 30 and on spirit crystal sword vipermagi p crown,2xsoj,magefists,or chancies, get war trav. blizzard is best with synergies- ice blast is your best bet
don't use glacial spike as it takes to much mana. 63%fcr is basic for normal and nm mf.-- Of course 105% is optimal for hell.

merc should always be imo-- norm--- defensive act2- after nm choose might or holy freeze as your merc will do more damage

I know when i play diablo2 i play through all the acts in single games to collect waypoints and make it fun in ways that make me a more skilled player as botting is very prevalent

Have fun....

Reach 105 FCR BP. Always.

Skills:
Blizzard > Cold Mastery (125(At least) - 175(Max) percent with +skill Gear) > Ice Blast > Glacial Spike > Ice Bolt

Merc(Basic Setup):
Act 2 Might Aura
Andy
Treachery
Insight

I heard People put points into meteor for cold immunes should i do that?

If u do that it s another build called meteorb
Blizzard build is only based on cold to MF pits, AT and some bosses